CXCL12 and neoplasm: Studies have shown that activated PSCs can establish an interaction with PDAC cells by secreting cytokines such as TGF-β, IL-6, stromal cell derived factor-1 (SDF-1), hepatocyte growth factor (HGF) and galactose lectin-1, which contribute to promoting the immunosuppressive properties of TME and supporting the aggressibility of PDAC and the main mechanism is to promote EMT of tumor cells, which is mediated by IL-6 (79, 80).